Infants and other incontinent individuals wear disposable absorbent articles to receive and contain urine and other bodily exudates. Absorbent articles having fixed sides have been popular for use in adult incontinence articles and children's toilet-training articles because it is desirable to have an absorbent article which is very garment-like in appearance and feel. (As used herein, "articles having fixed sides" refer to disposable articles such as adult incontinence briefs and training pants which are provided to the consumer in a pant-like configuration. Thus, the articles generally have the front and rear portions joined together to form a waist hoop and leg holes. This is unlike conventional diapers which are provided to the consumer with the front and rear portions unjoined.) For adults, the garment-like appearance and feel can help reduce any embarrassment associated with the use of incontinence articles. For children, especially in their toilet training stage, the garment-like feel and appearance can help the child distinguish the article, such as training pants, from a diaper and can help the child adjust to cloth undergarments.
With regard to disposable articles such as adult incontinence briefs and training pants, consumers are very conscious about the fit, containment characteristics and the overall appearance of the articles. One improvement that has become popular with consumers has been the addition of stretch or elasticity throughout different portions of the articles. One example of a commercially available disposable training pant is disclosed in U.S. Pat. No. 5,246,433 entitled "Elasticized Disposable Training Pant and Method of Making the Same", issued to Hasse et al. on Sep. 21, 1993.
Despite the improvements made to disposable articles having fixed sides, such articles generally include seams for joining the front and rear portions. The seams are often constructed by positioning the lateral edges of the front and rear portions of the article in a face-to-face relationship with one another and then gluing, sewing, heat sealing, pressure bonding or ultrasonically sealing the edges to form flanges or fin seams. Flanges or fin seams can be unsightly if located on the outwardly facing surface of the article or irritating to the wearer if located on the inward surface. Thus, attempts have been made to reduce the outwardly or inwardly extending portions of the flanges of fin seams. However, doing so may reduce the strength of the bond between the front and rear portions of the article which may allow the seam to fail during use.
Another important aspect of a disposable article is the cost of the article. Because the article is intended to be discarded, generally after a single use, consumers are very conscious of the cost of the article. Thus, it would be advantageous to be able to provide a seam that can be constructed economically on machinery that is very similar to that already in place. Further, it would be advantageous to reduce the amount of material that is needed to produce a satisfactory seam or that is wasted in attempting to make the seam preferable to the consumer.
Therefore, it is an object of the present invention to provide a method of making flangeless seams especially suited for use in disposable articles, such as disposable training pants, adult incontinence briefs and the like which are discrete, strong and economical to manufacture.
It is another object of the present invention to provide a method of making flangeless side seams which can be produced more quickly and easily than the sewn seams of the prior art and which provide a more garment-like appearance and are less irritating than the heat-sealed, adhesively bonded or ultrasonically sealed seams of the prior art.
It is yet another object of the present invention to provide a method of making flangeless side seams which reduces the amount of material needed to produce the seam as well as the material waste associated with providing a seam that is acceptable to the consumer.
It is still another object of the present invention to provide a method for manufacturing a flangeless seam for use with disposable articles that can be made on the machinery used to make currently available flange, fin or butt seams with minor modifications.
It is a further object of the present invention to provide a disposable article, such as disposable training pants, having flangeless seams.